Re-engaging with the Pure Theory of Law developed by Hans Kelsen and the other members of the Viennese School of Jurisprudence, this book looks at the causes and manifestations of uncertainty in international law. It considers both epistemological uncertainty as to whether we can accurately perceive norms in international law, and ontological problems which occur inter alia where two or more norms conflict. The book looks at these issues of uncertainty in relation to the foundational doctrines of public international law, including the law of self-defence under the United Nations Charter, customary international law, and the interpretation of treaties. In viewing international law through the lens of Kelsen's theory Joerg Kammerhofer demonstrates the importance of the theoretical dimension for the study of international law and offers a critique of the recent trend towards pragmatism and eclecticism in international legal scholarship. The unique aspect of the monograph is that it is the only book to apply the Pure Theory of Law as theoretical approach to international law, rather than simply being a piece of intellectual history describing it. This book will of great interest to students and scholars of public international law, legal theory and jurisprudence.

Re-engaging with the Pure Theory of Law developed by Hans Kelsen and the other members of the Viennese School of Jurisprudence, this book looks at the causes and manifestations of uncertainty in international law. It considers both epistemological uncertainty as to whether we can accurately perceive norms in international law, and ontological problems which occur inter alia where two or more norms conflict. The book looks at these issues of uncertainty in relation to the foundational doctrines of public international law, including the law of self-defence under the United Nations Charter, customary international law, and the interpretation of treaties.

In viewing international law through the lens of Kelsen's theory Jorg Kammerhofer demonstrates the importance of the theoretical dimension for the study of international law and offers a critique of the recent trend towards pragmatism and eclecticism in international legal scholarship. The unique aspect of the monograph is that it is the only book to apply the Pure Theory of Law as theoretical approach to international law, rather than simply being a piece of intellectual history describing it.

This book will of great interest to students and scholars of public international law, legal theory and jurisprudence.

Although customary international law (CIL) has been central to international law from its inception, it is often misunderstood. This edited volume remedies that problem by tracing the history of CIL and provides an in-depth study of its theory, practice, and interpretation. Its chapters tackle the big questions which surround this source of international law such as: what are the rules that regulate the functioning of CIL as a source of international law? Can CIL be interpreted? Where do lines between identification, interpretation, application, and modification of a rule of CIL lie? Using recent developments, this volume revisits old debates and resolves them by proffering new and innovative solutions. With detailed examples from international and national courts, it places CIL in a range of settings to explain, explore and reflect upon this developing and highly significant field. This title is also available as Open Access on Cambridge Core.

Expropriation is a hotly debated issue in international investment law. This is the first study to provide a detailed analysis of its norm-theoretical dimension, setting out the theoretical foundations underlying its understanding in contemporary legal scholarship and practice. Joerg Kammerhofer combines a doctrinal discussion with a theoretical analysis of the structure of the law in this area, undertaking a novel approach that critically re-evaluates existing case-law and writings. His approach critiques the arguments for a single expropriation norm based on custom, interpretation and arbitral precedents within international investment law, drawing also on generalist international legal thought, to show that both cosmopolitan and sovereigntist arguments are largely political, not legal. This innovative work will help scholars to understand the application of theory to investment law and help specialists in the field to improve their arguments.

International Legal Positivism in a Post-Modern World provides fresh perspectives on one of the most important and most controversial families of theoretical approaches to the study and practice of international law. The contributors include leading experts on international legal theory who analyse and criticise positivism as a conceptual framework for international law, explore its relationships with other approaches and apply it to current problems of international law. Is legal positivism relevant to the theory and practice of international law today? Have other answers to the problems of international law and the critique of positivism undermined the positivist project and its narratives? Do modern forms of positivism, inspired largely by the theoretically sophisticated jurisprudential concepts associated with Hans Kelsen and H. L. A. Hart, remain of any relevance for the international lawyer in this 'post-modern' age? The authors provide a wide variety of views and a stimulating debate about this family of approaches.

International Legal Positivism in a Post-Modern World provides fresh perspectives on one of the most important and most controversial families of theoretical approaches to the study and practice of international law. The contributors include leading experts on international legal theory who analyse and criticise positivism as a conceptual framework for international law, explore its relationships with other approaches and apply it to current problems of international law. Is legal positivism relevant to the theory and practice of international law today? Have other answers to the problems of international law and the critique of positivism undermined the positivist project and its narratives? Do modern forms of positivism, inspired largely by the theoretically sophisticated jurisprudential concepts associated with Hans Kelsen and H. L. A. Hart, remain of any relevance for the international lawyer in this 'post-modern' age? The authors provide a wide variety of views and a stimulating debate about this family of approaches.